Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
DTC Descriptors
DTC C0880 00: Device Voltage Reference Output 2 CircuitDTC C0890 00: Device Voltage Reference Output 3 Circuit
DTC C1115 08: Manual Trailer Brake Apply Request Switch Signal Invalid
DTC C1115 5A: Manual Trailer Brake Apply Request Switch Signal Plausibility Failure
DTC C1116 00: Manual Trailer Brake Apply Request Signal 1
DTC C1117 00: Manual Trailer Brake Apply Request circuit Signal 2
DTC C1118 00: Trailer Brake Control Sensitivity Switch Circuit
DTC C1118 08: Trailer Brake Control Sensitivity Switch Circuit Signal Invalid
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
5-Volt Reference | C0880 00, C0890 00, C1116 00, C1117 00 | C1116 00, C1117 00 | C0880 00, C0890 00, C1117 00 | -- |
Redundant Manual Apply Signal | C1117 00 | C1117 00 | C0890 00, C1117 00 | C1115 08, C1115 5A |
Manual Apply Signal | C1116 00 | C1116 00 | C0890 00, C1116 00, C1117 00 | C1115 08, C1115 5A |
User Gain switch Signal | C1118 00 | C1118 00 | C1118 00 | -- |
Low Reference | -- | C1116 00, C1117 00, C1118 00 | -- | -- |
Circuit/System Description
The trailer brake control module (TBCM) system has a control panel with the trailer gain and manual apply switches, and is located on the instrument panel to the left of the steering column. The control panel and switches allows you to adjust the amount of output, referred to as trailer gain, available to the electric trailer brakes and allows you to manually apply the trailer brakes. The Trailer Brake Control Panel, and switches is used along with the Trailer Brake Display Page on the DIC to adjust and display power output to the trailer brakes.
Conditions for Running the DTC
| • | Battery voltage is 9.5-17 volts. |
| • | The module is powered up and completes initialization. |
Conditions for Setting the DTC
C0880 00 or C0890 00
The TBCM detects the 5-volt reference circuit voltage is less than 4.8 volts or greater than 5.2 volts.
C1115 08 or C1115 5A
| • | The TBCM detects the manual apply switch is applied before the ignition is cycled OFF, and continuously applied for 30 seconds after ignition is cycled to ON. |
| • | The TBCM detects the manual apply switch is applied continuously for 5 minutes. |
| • | The fault is detected if the manual apply switch input and redundant apply switch input exceeds a threshold for an extended amount of time. |
C1116 00
| • | The TBCM detects a short to ground, open or a short to voltage on the manual apply signal circuit. |
| • | The TBCM detects a open on the low reference circuit. |
C1117 00
| • | The TBCM detects a short to ground, open or a short to voltage on the redundant manual apply signal circuit. |
| • | The TBCM detects a short to voltage on the manual apply signal circuit. |
| • | The TBCM detects a open on the low reference circuit. |
C1118 00
| • | The TBCM detects a short to ground, open or a short to voltage on the user gain signal circuit. |
| • | The TBCM detects a open on the low reference circuit. |
C1118 08
| • | The TBCM detects the user gain switch is applied before the ignition is cycled OFF, and continuously applied for 30 seconds after ignition is cycled to ON. |
| • | The TBCM detects the user gain switch is applied continuously for 5 minutes. |
Action Taken When the DTC Sets
| • | The trailer brake control will be disabled for the remainder of the ignition cycle. |
| • | The driver information center (DIC) will display Service Trailer Brake System. |
Condition for Clearing the DTC
| • | The condition for the DTC is no longer present. |
| • | The TBCM clears the history DTC when a current DTC is not detected in 40 consecutive drive cycles. |
Reference Information
Schematic Reference
Trailer Brake Control Schematics
Connector End View Reference
Trailer Brake Control Connector End Views
Description and Operation
Trailer Brake Controls Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
Ignition ON, observe the scan tool trailer brake controls user gain parameter. The reading should be between 0-100 percent, and change with operating the gain switch up or gain switch down.
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the trailer brake controller switch.
- Ignition OFF, wait 60 seconds, test for less than 5 ohms of resistance between the low reference circuit terminal 8 and ground.
- Ignition ON, test for 4.8 - 5.2 volts between the 5-volt reference circuit terminal 3 and ground.
- Verify the scan tool Manual Apply Switch parameter is less than 5 percent.
- Install a 3A fused jumper wire between the signal circuit terminal 4 and the 5-volt reference circuit terminal 3. Verify the scan tool Manual Apply Switch parameter is greater than 90 percent.
- Verify the scan tool Redundant Manual Apply Switch parameter is greater than 90 percent.
- Install a 3A fused jumper wire between the signal circuit terminal 5 and the 5-volt reference circuit terminal 3. Verify the scan tool Redundant Manual Apply Switch parameter is less than 5 percent.
- Ignition ON, test for 4.8 - 5.2 volts between the 5-volt reference circuit terminal 6 and ground.
- If all circuits test normal, test or replace the trailer brake controller switch panel.
| ⇒ | If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the TBCM. |
| ⇒ | If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the TBCM. |
| ⇒ | If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the TBCM. |
| ⇒ | If greater than the specified range, test the signal circuit terminal 4 for a short to voltage. If the circuit tests normal, replace the TBCM. |
| ⇒ | If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the TBCM. |
| ⇒ | If less than the specified range, test the signal circuit terminal 5 for a short to voltage. If the circuit tests normal, replace the TBCM. |
| ⇒ | If greater than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the TBCM. |
| ⇒ | If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the TBCM. |
| ⇒ | If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the TBCM. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for TBCM replacement, setup, and programming |
